The fifth planet out from the Sun is the most tremendous of all the planets in our solar system. Jupiter, or "The Gas Giant," is two and a half times more massive than Mercury, Venus, Mars, Earth, Uranus and Neptune combined. With a mean radius of 43,441 miles, it's unimaginable what secrets lie within it. The mysteries of the universe may never be fully discovered, but here are ten interesting facts about Jupiter. 1. Jupiter is the Fastest Spinning Planet Jupiter spins at a speed of 28,273 miles per hour, which is almost 28 times the speed of Earth. It takes, on average, 10 hours for Jupiter to make a full rotation, meaning that Jupiter also has the shortest days of all the planets in our Solar System. Unlike Earth, it is a gas planet, which means that it does not spin as a solid sphere. The equator of the gas giant spins a little faster than the rest of its mass, and this forces it to bulge out in this area. 2. The Gas Giant Has Rings After a five-year disappearance, Charles